000 AXNT20 KNHC 112348 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUN 11 2013 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA... CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA... NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2245 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 11N44W TO 1N46W MOVING W AT 20 KT. THE WAVE LIES WITHIN A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 42W-47W. A TROPICAL WAVE EXTENDS FROM 15N76W TO 3N77W MOVING W AT 20 KT. THE WAVE IS MOSTLY INLAND OVER COLOMBIA. THE WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER THAT RESIDES OVER THE SW CARIBBEAN. NUMEROUS STRONG CONVECTION IS FROM 7N-11N BETWEEN 73W-77W OVER COLOMBIA...AND FROM 8N-10N BETWEEN 77W-82W OVER PANAMA. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF SENEGAL NEAR 14N17W TO 11N21W. THE ITCZ BEGINS NEAR 11N21W AND CONTINUES ALONG 5N30W 6N45W 5N54W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-7N BETWEEN 25W-34W. ISOLATED MODERATE/STRONG CONVECTION IS FROM 2N-8N BETWEEN 35W-41W. ...DISCUSSION... THE GULF OF MEXICO... WEAK SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1020 MB HIGH NEAR 30N88W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER THE BAY OF CAMPECHE. LIGHT ANTI-CYCLONIC WINDS ARE AROUND THE HIGH CENTER INCREASING UP TO 10-15 KT OVER THE WESTERN GULF. A SURFACE TROUGH...REMNANTS OF A TROPICAL WAVE...IS ALONG 27N82W TO 24N82W. THE COMBINATION OF THE TROUGH AND DAYTIME HEATING AND INSTABILITY ARE HELPING SUPPORT SHOWERS/THUNDERSTORMS THROUGHOUT THE FLORIDA PENINSULA. ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO OVER THE NW GULF ASSOCIATED WITH DIFFLUENT FLOW ALOFT BETWEEN THE UPPER RIDGE OVER THE BASIN AND AN UPPER LEVEL LOW WEST OF CENTRAL MEXICO. AN ELONGATED UPPER TROUGH IS ALSO PUSHING SOUTH OVER THE FLORIDA PANHANDLE...WHICH MAY BE CONTRIBUTING TO THE SHOWER/THUNDERSTORM ACTIVITY OVER THE FLORIDA PENINSULA. SURFACE RIDGING WILL REMAIN THE DOMINATE FEATURE OVER THE NEXT SEVERAL DAYS. SHOWERS AND THUNDERSTORMS WILL REMAIN LIKELY OVER THE WESTERN GULF...AND OVER FLORIDA. THE CARIBBEAN SEA... MUCH OF THE WESTERN CARIBBEAN WATERS ARE EXPERIENCING FAIR CONDITIONS DUE TO DRY AIR ALOFT BETWEEN AN UPPER LEVEL RIDGE OVER THE GULF OF MEXICO...AND AN UPPER LEVEL TROUGH EXTENDING FROM THE MONA PASSAGE TO COSTA RICA. HOWEVER...HEAVY SHOWERS/THUNDERSTORMS ARE ACROSS CENTRAL AND EASTERN CUBA ASSOCIATED WITH DAYTIME HEATING AND INSTABILITY. A TROPICAL WAVE MOVING THROUGH THE SW CARIBBEAN IS ALSO PRODUCING A LARGE AREA OF CONVECTION OVER NORTHERN COLOMBIA AND PANAMA. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS. CONVECTION NEAR THE WAVE IS LIKELY BEING ENHANCED BY THE UPPER TROUGH. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO OVER MUCH OF NORTHERN CENTRAL AMERICA. THE UPPER TROUGH IS PROVIDING MOIST DIFFLUENT FLOW ALOFT OVER THE EASTERN CARIBBEAN...WHICH SUPPORTS SHOWERS/THUNDERSTORMS OVER HISPANIOLA. A FEW ISOLATED LOW-LEVEL SHOWERS ARE ALSO EMBEDDED IN THE 15-20 KT TRADEWIND FLOW PRESENT THROUGHOUT THE AREA. STRONGER WINDS UP TO 25 KT ARE NEAR THE COAST OF COLOMBIA. MOIST CONDITIONS ARE EXPECTED TO REMAIN OVER THE SW CARIBBEAN AS THE WAVE TRACKS WESTWARD. THE UPPER TROUGH NEAR THE MONA PASSAGE WILL GRADUALLY LIFT NORTH OVER THE NEXT COUPLE OF DAYS AS A NEW TROUGH DIPS SOUTH OVER CUBA. HISPANIOLA... A CLUSTER OF HEAVY SHOWERS/THUNDERSTORMS IS CURRENTLY OVER HAITI FROM 18N-20N BETWEEN 71W-73W...WHILE ISOLATED SHOWERS AND THUNDERSTORMS DOT THE REMAINDER OF THE ISLAND. THIS ACTIVITY IS DUE TO A COMBINATION OF DAYTIME HEATING AND INSTABILITY PRESENT ON MOST AFTERNOONS...AND DIFFLUENT FLOW ALOFT AROUND AN UPPER TROUGH EXTENDING FROM THE MONA PASSAGE TO COSTA RICA. THIS UPPER TROUGH WILL GRADUALLY LIFT NORTH OF THE NEXT 24-28 HOURS...BUT WILL LIKELY CONTINUE TO IMPACT THE ISLAND UNTIL THEN. THE ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE OVER THE FAR WESTERN ATLC WEST OF 76W ASSOCIATED WITH AN ELONGATED UPPER TROUGH DIPPING SOUTH OVER THE FLORIDA PANHANDLE. A NARROW UPPER TROUGH IS ALSO TO THE EAST ALONG 73W PROVIDING DIFFLUENT FLOW OVER THE EASTERN CARIBBEAN AND SUPPORTING ISOLATED SHOWERS SOUTH OF 30N BETWEEN 62W-71W. THE REMAINDER OF THE AREA IS DOMINATED BY ONE LARGE AND BROAD SURFACE RIDGE ANCHORED BY A 1028 MB HIGH NEAR 30N39W. ALOFT...UPPER RIDGING IS ALONG 62W...AND 34W...WITH AN UPPER LEVEL TROUGH SANDWICHED BETWEEN THEM. THE UPPER TROUGH SUPPORTS A FEW HIGH CLOUDS...BUT NO NOTABLE WEATHER. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE A LARGE AREA OF SAHARAN DUST EXTENDS OFF THE COAST OF AFRICA AND CONTINUES TO NEAR 40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON